Polishing of strip metal

ABSTRACT

The metal strip to be polished is run through spaced drag and pull bridles to establish a tension on the strip portion therebetween. An abrasive device contacts a surface of the tensioned strip portion to polish such surface. The strip is run through the rolls of a leveler to continuously work the strip as it passes from the drag bridle to the abrasive device and thus relieve the strip of stresses and make more effective the tension on the strip so as to present a flat surface to said abrasive device. In so passing through the leveler, the strip is also elongated as in the usual tension leveling operation.

United States Patent Bandy 5] Feb. 29, 1972 154] POLISHING 0F STRIPMETAL [72] Inventor: [73] Assignee: Wean Industries, Inc., Youngstown,Ohio [22] Filed: Dec. 29, 1969 [21] App1.No.: 888,274

Kenneth L. Bandy, Youngstown, Ohio [52] U.S.Cl ..5l/5,51/75,51/323,

[51] Int. Cl ..B24b 7/00 [58] Field of Search ..51/5, 137, 139,74, 75,80A, 51/323, 324,112, 215 R [56] References Cited UNITED STATES PATENTSValette et a1. .15 1/5 Nye etal ..51/112 Bond ..51/5

Primary Examiner-William R. Armstrong Attorney-Michae1 Williams [57] 1ABSTRACT The metal strip to be polished is run through spaced drag andpull bridles to establish a tension on the strip portion therebetween.An abrasive device contacts a surface of the tensioned strip portion topolish such surface. The strip is run through the rolls of a leveler tocontinuously work the strip as it passes from the drag bridle to theabrasive device and thus relieve the strip of stresses and make moreeffective the tension on the strip so as to present a flat surface tosaid abrasive device. 1n so passing through the leveler, the strip isalso elongated as in the usual tension leveling operation.

8 Claims, 4 Drawing Figures Patented Feb. 29, 1972 3,645,046

ENTOR. K E NN ET H .BANDT A 7 rams e7 BYZ/wMMW POLISHING OF STRIP METALBACKGROUND AND SUMMARY Heretofore, insofar as I am aware, the surface ofmetal strip was polished by contacting one or both surfaces of the stripwith abrasive devices while the strip was tensioned therebetween. It wasfound that the strip was not presented in sufiiciently flat condition tothe abrasive device to produce a uniform polishing of the surface andthis deficiency was not overcome even by increase of tension to anultimate limit.

Many attempts have been made to overcome this deficiency,

without beneficial results. The problem encountered in the prior art wasthat the strip was not flat, particularly in a longitudinal direction,and I have solved this problem by placing a leveler between the dragbridle and the abrasive device. As a result of this solution, the stripis presented to the abrasive device in acceptable flat condition, freeof any canoeing effect, so that the latter uniformly polishes the stripsurface, without an increase in strip tension. I have further found thatthe abrasive action on the strip, and the slight bending of the stripabout the abrasive device backup roll, may form a canoeing configurationin the strip, and my invention further includes the disposition of finalbending rolls between the abrasive device and the pull bridle to relievesuch undesirable configuration.

DESCRIPTION OF THE DRAWING In the drawing accompanying this descriptionand forming a part of this specification, there is shown, for purposesof illustration, an embodiment which my invention may assume, and inthis drawing:

FIG. 1 is a schematic representation of a strip polishing line,illustrating my invention,

FIG. 2 is an enlarged fragmentary view of the strip, showing inexaggerated manner, an out-of-flat condition which my inventionovercomes, and

FIGS. 3 and 4 are fragmentary enlarged details of certain apparatusutilized in the line shown in FIG. 1.

DESCRIPTION OF PREFERRED EMBODIMENT The strip S is tensioned betweenspaced devices which may take any suitable form, and in the preferredembodiment herein disclosed such devices take the form of a drag bridlel and a pull bridle 11. It will be appreciated that other tensionproducing devices may be employed, such as an uncoiler reel with a dragthereon, and a coiler reel with a pull thereon.

However, in order to produce controlled tension in the magnituderequired, the drag and pull bridles are preferred and, as shown, thedrag bridle takes the strip from an uncoiler reel 12 and the pull bridle11 delivers the strip to a coiler reel 14.

Abrasive devices 15 and 16 are disposed to effect polishing of theopposite surfaces of the strips S and these devices may be of anycommercially available form. In the illustrated embodiment each abrasivedevice comprises an endless abrasive belt 17, such as emery cloth or thelike, trained over a pair of rolls 18 and 19, the roll 18 beingpreferably driven and the roll 19 being an idler roll, so that theendless belt scrubs the strip surface and polishes the same. A backuproll 20 opposes each of the rolls 19 to hold the strip in contact withthe abrasive belt.

The foregoing description is illustrative of prior construction whereindrag and pull bridles establish tension on the strip, and this tensionhas been in the order of 50,000 pounds per square inch. Yet, despitesuch tension, and even an increase in such tension, it has been foundthat the strip has not been presented to the abrasive devices 15 and 16in sufficiently flat condition to produce uniform polishing of the stripsurfaces. As seen in FIG. 2, a common out-of-flat condition isillustrated in exaggerated manner, wherein the sheet has a waveformation running longitudinally thereof.

It has been discovered that disposition of strip working rolls betweenthe drag bridle and the abrasive device 15 results in to a desiredcondition, and this is beflattening of the strip lieved to be broughtabout by a continuous working of the strip to relieve stresses thereinso that the tension force is more effective to straighten the strip.

As shown in FIG. 1, a strip leveler apparatus 21 is interposed betweenthe drag bridle l0 and the abrasive device 15, and a final-bendflattening apparatus 22 is disposed between the abrasive device 16 andthe pull bridle II. The leveler 21 may take the form shown in FIG. 3,wherein working rolls 23, 24 engage respective opposite sides of thestrip and work the strip to relieve stresses therein. Backup rolls 25,26 support the respective working rolls against deflection. The workingrolls 23, 24 and their backup rolls 25, 26 are carried by respectiveframes 27, 28 which are relatively adjustable so that the working rollsmay be adjusted to vary the amount the strip is worked by the rolls 23,24.

In order to remove any canoeing of the strip which may be caused by theworking rolls 23, 24 as they relieve stresses in the strip, the latteris engaged by working rolls 29, 30 as it leaves the rolls 23, 24. Duringthe abrading operation, the strip has a slight wrap about the backuprolls 20, 20 of the abrasive devices l5, l6 and to remove any canoeingin the strip which may be caused by such wrap, and to relieve anystresses introduced into the strip by the grinding operation, thefinal-bend flattening apparatus 22 is utilized. This apparatus maycomprise working rolls 3], 32 and backup rolls 33, 34 similar to therolls 23, 24, 25 and 26.

I claim:

1. The method of polishing the surface of a thin metal strip, whichcomprises passing the strip through a drag bridle and a spaced pullbridle to establish tension on the strip portion between the bridles,contacting a surface of tensioned strip portion with an abrasive deviceto polish such surface, and continuously passing said tensioned stripportion through the rolls of a leveler before it reaches said abrasivedevice to relieve stresses in said strip portion and combine with striptension to present a flat surface to said abrasive device.

2. The method of claim 1 and including the step of passing said stripportion through bending rolls located between said abrasive device andsaid pull bridle to remove canoeing and to relieve stresses set up insaid strip by the abrasive action.

3. The method of claim 1 wherein opposite surfaces of said strip portionare contacted by abrasive devices to polish both surfaces of said strip.

4. The method of claim 1 wherein said strip is engaged by working rollsas said strip portion leaves said leveler rolls and before it reachessaid abrasive device to remove any canoeing of the strip which may becaused by the leveler operation.

5. Apparatus for polishing the surface of a longitudinally moving thinmetal strip, comprising a drag bridle and pull bridle spaced from saiddrag bridle, said strip passing from said drag bridle to said pullbridle whereby the strip portion between said bridles is tensioned, anabrasive device having an abrasive surface contacting a surface of saidstrip portion to polish such surface, and leveling rolls between saiddrag bridle and said abrasive device, said rolls being arranged tocontinuously work the strip as it passes from said drag bridle to saidabrasive device, whereby stresses in said strip portion are relieved andstrip tension more effectively utilized to present a flat surface tosaid abrasive device.

6. Apparatus according to claim 5 and further including strip bendingrolls located between said abrasive device and said pull bridle toremove canoeing and to relieve stresses in the strip caused by theabrasive action.

7. Apparatus according to claim 5 wherein abrasive devices contactopposite surfaces of the strip to polish the same.

8. Apparatus according to claim 5 wherein said strip is engaged byworking rolls as said strip portion leaves said leveling rolls andbefore it reaches said abrasive device to remove any canoeing of thestrip which may be caused by the strip leveling operation.

1. The method of polishing the surface of a thin metal strip, whichcomprises passing the strip through a drag bridle and a spaced pullbridle to establish tension on the strip portion between the bridles,contacting a surface of tensioned strip portion with an abrasive deviceto polish such surface, and continuously passing said tensioned stripportion through the rolls of a leveler before it reaches said abrasivedevice to relieve stresses in said strip portion and combine with striptension to present a flat surface to said abrasive device.
 2. The methodof claim 1 and including the step of passing said strip portion throughbending rolls located between said abrasive device and said pull bridleto remove canoeing and to relieve stresses set up in said strip by theabrasive action.
 3. The method of claim 1 wherein opposite surfaces ofsaid strip portion are contacted by abrasive devices to polish bothsurfaces of said strip.
 4. The method of claim 1 wherein said strip isengaged by working rolls as said strip portion leaves said leveler rollsand before it reaches said abrasive device to remove any canoeing of thestrip which may be caused by the leveler operation.
 5. Apparatus forpolishing the surface of a longitudinally moving thin metal strip,comprising a drag bridle and pull brIdle spaced from said drag bridle,said strip passing from said drag bridle to said pull bridle whereby thestrip portion between said bridles is tensioned, an abrasive devicehaving an abrasive surface contacting a surface of said strip portion topolish such surface, and leveling rolls between said drag bridle andsaid abrasive device, said rolls being arranged to continuously work thestrip as it passes from said drag bridle to said abrasive device,whereby stresses in said strip portion are relieved and strip tensionmore effectively utilized to present a flat surface to said abrasivedevice.
 6. Apparatus according to claim 5 and further including stripbending rolls located between said abrasive device and said pull bridleto remove canoeing and to relieve stresses in the strip caused by theabrasive action.
 7. Apparatus according to claim 5 wherein abrasivedevices contact opposite surfaces of the strip to polish the same. 8.Apparatus according to claim 5 wherein said strip is engaged by workingrolls as said strip portion leaves said leveling rolls and before itreaches said abrasive device to remove any canoeing of the strip whichmay be caused by the strip leveling operation.